Is my Bosch ETM/throttle-body dead? -- 2005 S40 T5

Fourthbean · Post by **Fourthbean** » 27 Dec 2016, 10:46

Good day!

So a tad bit of BACK-STORY, I purchased this 2005 S40 T5 that was already experiencing a "reduced power mode" condition. Turning the car off for a few minutes would clear it but go right back after a minute or two of driving.

PROBLEM:
Purchased a VIDA system hoping to get some accurate data before replacing parts. Pulled codes like the following and figured I'd better purchase another ETM:

ECM-929D
ECM-9270

I didn't want to shell out $500 for a brand new ETM so I purchased a used on on Ebay.

With the new ETM/Throttle body installed I'm getting similar codes and similar behavior from the car.

1 thing I found interesting was that I had cleared the codes, gone for a drive, everything was working great. Then while I was idling in the garage with my foot off the accelerator pedal it went into Reduced Power Mode.

I have taken some pictures from VIDA showing some error codes that are currently in the ECM.

The graph I have uploaded is with the car off, all of the sensors seem to follow each other pretty well but I'm not sure what a "good" ETM feedback looks like. I also have some freeze frame data where expected throttle position is one value, throttle position is another, and nominal throttle is yet another. Not sure if that is expected behavior or if that's why the code was thrown.

I did ohm out the wiring harness between the ETM motor and the ECU, came out to 8ohms for each and seemed stable.

QUESTION:
1. Does anyone have an opinion on what I should chase next? I'm asking the Ebay seller if he has another ETM he could ship me as my first guess is that both of the ones I have are failing.

2. Is there something else I should be looking at in VIDA to see what could be going on?

I certainly appreciate any insight in case I'm missing something.

Post by **MadeInJapan** » 28 Dec 2016, 09:24

I wish I knew what to tell you...I have no experience with the ETM's on these cars.

Fourthbean · Post by **Fourthbean** » 30 Dec 2016, 20:03

OK, I've been playing around with the car some more. Interesting tidbit is that each time I get a freeze frame for ECM-9270 the "throttle angle" is always 17.25% where the Nominal throttle angle and desired throttle angle are both different values that are independent of each other as well.

This is 3.77 volts on the Potentiometer 2 and 1.24 volts on potentiometer 1 if memory serves right.

I'm not sure what the significance of this number is.

I'm going to try and find where I can measure the supply voltage for the PWM control of the throttle. While the engine is off right now it doesn't go through its normal check when you turn the key to "2". It did throw a code, without turning the engine on. It was the one for adaptation not working, 9240 I think. Freeze data showed throttle angle at 17.25% where desired was down at like 8%. Again that 17.25 number...

I'm letting my battery charge on my laptop then I will see about swapping back to my original throttle body to see if it acts the same.

Fourthbean · Post by **Fourthbean** » 31 Dec 2016, 10:12

Wired up an oscilloscope to my laptop and tied into the Throttle motor wires. I was able to reproduce the mismatch of throttle angle and expected throttle angle. When the actual throttle angle dropped off the throttle motor was no longer receiving any voltage. This leads me to believe either a wiring issue or my ECM is bad. Gonna see if I can trace the wires back and then I guess I'll get someone to rebuild my ECU. I've got a chinese VIDA but it looks like I can't load software with it otherwise I'd do a junkyard ECM.

kevins s70 · Post by **kevins s70** » 15 Jan 2017, 07:03

I am having a similar problem on a non turbo V50. What did you finally find? I don't have a scope but there would need to be voltage on the ETM to keep the throttle open - varied by the ECU dependent on how much the throttle needs to be opened.